A pattern recognition system, such as a speech recognition system, takes an input signal and attempts to decode the signal to find a pattern represented by the signal. For example, in a speech recognition system, a speech signal is received by the recognition system and is decoded to identify a string of words represented by the speech signal.
Input signals can be corrupted by some form of noise. To improve performance of the pattern recognition system, an estimate of the amount of noise in a signal can be made. This estimate can be used to filter the signal and improve performance of the system.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.